I think we learn that there is value even in bad implementation. For example, a lot of what custom tags promised in ColdFusion 20 years are finding fruition in client-side components.

Likewise, I think there's value in scoped work, as opposed to the mess than can come of globals. Otherwise you find yourself hard-coding !important when you need to make something work.

I prefer "build on lessons learned from" to "going back to" :-)